Cerebrolysin improves cognitive performance in rats after mild traumatic brain injury

Acute Combined Cerebrolysin and Nicotinamide Administration Promote Cognitive Recovery Through Neuronal Changes in the Hippocampus of Rats with Permanent Middle Cerebral Artery Occlusion

Stroke is one of the leading causes of disability worldwide, where the Hippocampus (HPC) is affected. HPC organizes memory, which is a cognitive domain compromised after a stroke, where cerebrolysin (CBL) and Nicotinamide (NAM) have been recognized as potentially therapeutic. In this study, we aimed to evaluate the efficacy of a combined administration of CBL and NAM in a rat stroke model. Male Sprague-Dawley rats (n = 36) were divided into four groups: saline (pMCAO - Saline), CBL (pMCAO + CBL), NAM (pMCAO + NAM), and experimental (pMCAO + CBL-NAM) (n = 9 per group). A permanent middle cerebral artery occlusion (pMCAO) was induced through electrocauterization of the middle cerebral artery, followed by the administration of CBL (2.5 ml/kg), NAM (500 mg/kg) or combined immediately after skin suture, as well as at 24, 48, and 72 h post-surgery. The rats were evaluated in the novel object recognition test; hippocampal infarct area measurement; reconstruction of neurons from CA1 for Sholl analysis; and, measurement of brain-derived neurotrophic factor (BDNF) levels near the infarct zone. Our findings revealed that the administration of CBL or NAM induced infarct reduction, improved cognition, and increased BDNF levels. Moreover, a combination of CBL and NAM increased dendritic intersection in CA1 pyramidal neurons. Thus, the combined administration of CBL and NAM can promote cognitive recovery after a stroke, with infarct reduction, cytoarchitectural changes in HPC CA1 neurons, and BDNF increase. Our findings suggest that this combination therapy could be a promising intervention strategy for stroke.

Nature's Toolbox for Alzheimer's Disease: A Review on the Potential of Natural Products as Alzheimer's Disease Drugs

Numerous clinical trials involving natural products have been conducted to observe cognitive performances and biomarkers in Alzheimer's Disease (AD) patients. However, to date, no natural-based drugs have been approved by the FDA as treatments for AD. In this review, natural product-based compounds that were tested in clinical trials from 2011 to 2023, registered at www.clinicaltrials.gov were reviewed. Thirteen compounds, encompassing 7 different mechanisms of action were covered. Several observations were deduced, which are: i) several compounds showed cognitive improvement, but these improvements may not extend to AD, ii) compounds that are endogenous to the human body showed better outcomes, and iii) Docosahexaenoic acid (DHA) and cerebrolysin had the most potential as AD drugs among the 13 compounds. Based on the current findings, natural products may be more suitable as a supplement than AD drugs in most cases. However, the studies covered here were conducted in a relatively short amount of time, where compounds acting on AD pathways may take time to show any effect. Given the diverse pathways that these natural products are involved in, they may potentially produce synergistic effects that would be beneficial in treating AD. Additionally, natural products benefit from both physicochemical properties being in more favorable ranges and active transport playing a more significant role than it does for synthetic compounds.

Cerebrolysin potentiates the antidepressant effect of lithium in a rat model of depression

RATIONALE

Depression is the most prevalent psychiatric disorder worldwide. Although numerous antidepressant treatments are available, there is a serious clinical concern due to their severe side effects and the fact that some depressed patients are resistant to them. Lithium is the drug of choice for bipolar depression and has been used as adjunct therapy with other groups of antidepressants.

OBJECTIVES

The present study aims to investigate the effect of lithium augmentation with cerebrolysin on the neurochemical, behavioral and histopathological alterations induced in the reserpine model of depression.

METHODS

The animals were divided into control and reserpine-induced model of depression. The model animals were further divided into rat model of depression, rat model treated with lithium, rat model treated with cerebrolysin and rat model treated with a combination of lithium and cerebrolysin.

RESULTS

Treatment with lithium, cerebrolysin, or their combination alleviated most of the changes in behavior, oxidative stress parameters, acetylcholinesterase and monoamines in the cortex and hippocampus of the reserpine-induced model of depression. It also improved the alterations in brain-derived neurotrophic factor (BDNF) and histopathology induced by reserpine.

CONCLUSIONS

The augmentation of lithium with cerebrolysin showed a clear beneficial effect in the present model of depression suggesting the use of cerebrolysin as an adjuvant in antidepressant treatment.

Weight-drop model as a valuable tool to study potential neurobiological processes underlying behavioral and cognitive changes secondary to mild traumatic brain injury

The pathophysiology of post-traumatic brain injury (TBI) behavioral and cognitive changes is not fully understood, especially in its mild presentation. We designed a weight drop TBI model in mice to investigate the role of neuroinflammation in behavioral and cognitive sequelae following mild TBI. C57BL/6 mice displayed depressive-like behavior at 72 h after mild TBI compared with controls, as indicated by a decrease in the latency to first immobility and climbing time in the forced swim test. Additionally, anxiety-like behavior and hippocampal-associated spatial learning and memory impairment were found in the elevated plus maze and in the Barnes maze, respectively. Levels of a set of inflammatory mediators and neurotrophic factors were analyzed at 6 h, 24 h, 72 h, and 30 days after injury in ipsilateral and contralateral hemispheres of the prefrontal cortex and hippocampus. Principal components analysis revealed two principal components (PC), which represented 59.1% of data variability. PC1 (cytokines and chemokines) expression varied between both hemispheres, while PC2 (neurotrophic factors) expression varied only across the investigated brain areas. Our model reproduces mild TBI-associated clinical signs and pathological features and might be a valuable tool to broaden the knowledge regarding mild TBI pathophysiology as well as to test potential therapeutic targets.

Cerebrolysin in Patients with TBI: Systematic Review and Meta-Analysis

TBI (traumatic brain injury) is one of the most common causes of deaths and failure to return to society according to the latest statistics. Cerebrolysin is a drug approved for use in patients diagnosed with TBI. It is a mixture of neuropeptides derived from purified porcine brain proteins and multiple experimental studies have proven its neuroprotective and neurorestorative properties both in vitro and in vivo. In our meta-analysis, we analyze the latest clinical study reports on the use of Cerebrolysin in patients with TBI. The authors searched the databases: Pub Med, Cinahl, Web Of Science, and Embase from database inception until 11th July 2022. Ten clinical studies were eligible and included in the final analysis, including both retrospective and prospective studies of 8749 patients. Treatment with Cerebrolysin was associated with a statistically significant change in GCS and GOS. Mortality of any cause and the length of stay was not affected by the treatment. Our findings support and confirm the beneficial effects of Cerebrolysin treatment on the clinical outcome of patients after TBI. Further multi-center studies to optimize dosing and time of administration should be conducted.

Overexpressed ski efficiently promotes neurorestoration, increases neuronal regeneration, and reduces astrogliosis after traumatic brain injury

Traumatic brain injury (TBI) survivors suffer from long-term disability and neuropsychiatric sequelae due to irreparable brain tissue destruction. However, there are still few efficient therapies to promote neurorestoration in damaged brain tissue. This study aimed to investigate whether the pro-oncogenic gene ski can promote neurorestoration after TBI. We established a ski-overexpressing experimental TBI mouse model using adenovirus-mediated overexpression through immediate injection after injury. Hematoxylin-eosin staining, MRI-based 3D lesion volume reconstruction, neurobehavioral tests, and analyses of neuronal regeneration and astrogliosis were used to assess neurorestorative efficiency. The effects of ski overexpression on the proliferation of cultured immature neurons and astrocytes were evaluated using imaging flow cytometry. The Ski protein level increased in the perilesional region at 3 days post injury. ski overexpression further elevated Ski protein levels up to 14 days post injury. Lesion volume was attenuated by approximately 36-55% after ski overexpression, with better neurobehavioral recovery, more newborn immature and mature neurons, and less astrogliosis in the perilesional region. Imaging flow cytometry results showed that ski overexpression elevated the proliferation rate of immature neurons and reduced the proliferation rate of astrocytes. These results show that ski can be considered a novel neurorestoration-related gene that effectively promotes neurorestoration, facilitates neuronal regeneration, and reduces astrogliosis after TBI.

Treatment With an Angiopoietin-1 Mimetic Peptide Improves Cognitive Outcome in Rats With Vascular Dementia

Background and Purpose

Vascular dementia (VaD) is a complex neurodegenerative disease affecting cognition and memory. There is a lack of approved pharmacological treatments specifically for VaD. In this study, we investigate the therapeutic effects of AV-001, a Tie2 receptor agonist, in middle-aged rats subjected to a multiple microinfarct (MMI) model of VaD.

Methods

Male, 10-12 month-old, Wistar rats were employed. The following experimental groups were used: Sham, MMI, MMI+1 μg/Kg AV-001, MMI+3 μg/Kg AV-001, MMI+6 μg/Kg AV-001. AV-001 treatment was initiated at 1 day after MMI and administered once daily via intraperitoneal injection. An investigator blinded to the experimental groups conducted a battery of neuro-cognitive tests including modified neurological severity score (mNSS) test, novel object recognition test, novel odor recognition test, three chamber social interaction test, and Morris water maze test. Rats were sacrificed at 6 weeks after MMI.

Results

There was no mortality observed after 1, 3, or 6 μg/Kg AV-001 treatment in middle-aged rats subjected to MMI. AV-001 treatment (1, 3, or 6 μg/Kg) does not significantly alter blood pressure or heart rate at 6 weeks after MMI compared to baseline values or the MMI control group. Treatment of MMI with 1 or 3 μg/Kg AV-001 treatment does not significantly alter body weight compared to Sham or MMI control group. While 6 μg/Kg AV-001 treated group exhibit significantly lower body weight compared to Sham and MMI control group, the weight loss is evident starting at 1 day after MMI when treatment was initiated and is not significantly different compared to its baseline values at day 0 or day 1 after MMI. AV-001 treatment significantly decreases serum alanine aminotransferase, serum creatinine, and serum troponin I levels compared to the MMI control group; however, all values are within normal range. MMI induces mild neurological deficits in middle-aged rats indicated by low mNSS scores (<6 on a scale of 0-18). Compared to control MMI group, 1 μg/Kg AV-001 treatment group did not exhibit significantly different mNSS scores, while 3 and 6 μg/Kg AV-001 treatment induced significantly worse mNSS scores on days 21-42 and 14-42 after MMI, respectively. MMI in middle-aged rats induces significant cognitive impairment including short-term memory loss, long-term memory loss, reduced preference for social novelty and impaired spatial learning and memory compared to sham control rats. Rats treated with 1 μg/Kg AV-001 exhibit significantly improved short-term and long-term memory, increased preference for social novelty, and improved spatial learning and memory compared to MMI rats. Treatment with 3 μg/Kg AV-001 improves short-term memory and preference for social novelty but does not improve long-term memory or spatial learning and memory compared to MMI rats. Treatment with 6 μg/Kg AV-001 improves only long-term memory compared to MMI rats. Thus, 1 μg/Kg AV-001 treatment was selected as an optimal dose. Treatment of middle-aged rats subjected to MMI with 1 μg/Kg AV-001 significantly increases axon density, myelin density and myelin thickness in the corpus callosum, as well as increases synaptic protein expression, neuronal branching and dendritic spine density in the cortex, oligodendrocytes and oligodendrocyte progenitor cell number in the cortex and striatum and promotes neurogenesis in the subventricular zone compared to control MMI rats.

Conclusions

In this study, we present AV-001 as a novel therapeutic agent to improve cognitive function and reduce white matter injury in middle aged-rats subjected to a MMI model of VaD. Treatment of MMI with 1 μg/Kg AV-001 significantly improves cognitive function, and increases axon density, remyelination and neuroplasticity in the brain of middle-aged rats.

Pharmacotherapy for mild traumatic brain injury: an overview of the current treatment options

INTRODUCTION

Accounting for 90% of all traumatic brain injuries (TBIs), mild traumatic brain injury (mTBI) is currently the most frequently seen type of TBI. Although most patients can recover from mTBI, some may suffer from prolonged symptoms for months to years after injury. Growing evidence indicates that mTBI is associated with neurodegenerative diseases including dementias and Parkinson's disease (PD). Pharmacological interventions are necessary to address the symptoms and avoid the adverse consequences of mTBI.

AREAS COVERED

To provide an overview of the current treatment options, the authors herein review the potential drugs to reduce the secondary damage and symptom-targeted therapy as well as the ongoing clinical trials about pharmacotherapy for mTBI.

EXPERT OPINION

There has been no consensus on the pharmacotherapy for mTBI. Several candidates including n-3 PUFAs, melatonin, NAC and statins show potential benefits in lessening the secondary injury and improving neurological deficits in pre-clinic studies, which, however, still need further investigation in clinical trials. The current pharmacotherapy for mTBI is empirical in nature and mainly targets to mitigate the symptoms. Well-designed clinical trials are now warranted to provide high level evidence.

Applying a novel 3D hydrogel cell culture to investigate activation of microglia due to rotational kinematics associated with mild traumatic brain injury

Many investigations on mild traumatic brain injury (mTBI) aim to further understand how cells in the brain react to the mechanical forces associated with the injury. While it is known that rapid head rotation is a mechanism contributing to mTBI, establishing definitive thresholds for head rotation has proved challenging. One way to advance determining mechanisms and thresholds for injury is through in vitro models. Here, an apparatus has been designed that is capable of delivering rotational forces to three-dimensional (3D) hydrogel cell cultures. Using an in vitro model, we test the hypothesis that rotational kinematics can activate microglia suspended in a 3-dimensional mixed glia environment (absent neurons). The impact apparatus was able to deliver peak angular velocities of approximately 45 rad/s, a magnitude for angular velocity that in select literature is associated with diffuse brain injury. However, no measurable glial cell reactivity was observed in response to the rotational kinematics through any of the chosen metrics (nitric oxide, pro-inflammatory cytokine release and proportion of amoeboid activated microglia). The results generated from this study suggest that rotation of the glia alone did not cause activation - in future work we will investigate the effect of neuronal contributions in activating glia.

Cerebrolysin for vascular dementia

BACKGROUND

Although vascular dementia is the second most common cause of dementia globally, evidence-based treatments are still lacking. Cerebrolysin is a porcine brain-derived preparation that is said to have neurotrophic and neuroprotective activity. In many parts of the world Cerebrolysin, given as a series of daily intravenous infusions, is used as a potential intervention for vascular dementia. A previous Cochrane Review on Cerebrolysin in vascular dementia yielded inconsistent results. We wished to update the review to add new studies from the international literature and employ contemporary methods for appraising the strength of the evidence. This is the first update of a review first published in 2013.

OBJECTIVES

Primary: to assess the effect of Cerebrolysin on cognitive function, global function, and all-cause mortality in people living with vascular dementia. Secondary: to assess the adverse effects of Cerebrolysin and to assess the effect of Cerebrolysin on quality of life and caregiver burden.

SEARCH METHODS

We searched ALOIS, MEDLINE, Embase, PsycINFO, CINAHL, ISI Web of Knowledge, LILACS, the Cochrane Library, ClinicalTrials.gov, and the WHO ICTRP on 16 June 2017, 9 May 2018, and 9 May 2019. We expanded the search by adding four Chinese databases, searched from 1 January 2012 to 19 May 2019. We checked bibliographies of relevant papers identified and contacted pharmaceutical companies, trial authors, and experts in the field to identify any additional published or unpublished data.

SELECTION CRITERIA

We included all randomised controlled trials of Cerebrolysin used in people living with vascular dementia. We applied no language restriction.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion and evaluated their methodological quality. Data were extracted and analysed using mean differences (MDs) or standardised mean differences (SMDs) with 95% confidence intervals (95% CI) for continuous outcomes. We reported dichotomous outcomes as risk ratio (RR) with 95% CI. We assessed the strength of the available evidence using the GRADE approach.

MAIN RESULTS

We identified six randomised controlled trials with a total of 597 participants that were eligible for inclusion in the 2013 review. No new studies were eligible for inclusion in this update. Participants in the included studies, where dementia severity was reported, had mild to moderate severity of vascular dementia (four trials). The included studies tested varying doses and duration of Cerebrolysin treatment. Follow-up ranged from 15 days to three years. Five of included studies were conducted in China (three studies), Russia (one study), and Romania (one study), while relevant information of other study was unclear. Where details of funding were available, all studies were supported by the pharmaceutical industry (three studies). Cognitive function was measured using the Mini-Mental State Examination (MMSE) or Alzheimer's Disease Assessment Scale Cognitive Subpart, extended version (ADAS-cog+). Combining the MMSE and ADAS-cog+ data (three studies, 420 people), there was a beneficial effect of Cerebrolysin (SMD 0.36, 95% CI 0.13 to 0.58; very low-quality evidence). Global function was measured by Clinician's Interview-Based Impression of Change plus Caregiver Input (CIBIC+) or Investigator's Clinical Global Impression (CGI). We assessed response rates on these measures (the proportion of participants with a CIBIC+ score of < 3; or at least moderate improvement of the CGI rating at the last visit). There was a beneficial effect of Cerebrolysin (two studies, 379 participants, RR 2.69, 95% CI 1.82 to 3.98; very low-quality evidence). Only one trial described mortality and reported no deaths. Four studies reported adverse events; data from two studies (379 people) were in a format that permitted meta-analysis, and there was no difference in rates of adverse effects (RR 0.91, 95% CI 0.29 to 2.85; very low-quality evidence). No studies reported on quality of life or caregiver burden.

AUTHORS' CONCLUSIONS

Courses of intravenous Cerebrolysin improved cognition and general function in people living with vascular dementia, with no suggestion of adverse effects. However, these data are not definitive. Our analyses were limited by heterogeneity, and the included papers had high risk of bias. If there are benefits of Cerebrolysin, the effects may be too small to be clinically meaningful. There have been no new studies of Cerebrolysin in vascular dementia since the last Cochrane Review. Cerebrolysin continues to be used and promoted as a treatment for vascular dementia, but the supporting evidence base is weak. Adequately powered, methodologically robust trials are needed to properly assess the effects of Cerebrolysin in vascular dementia.

Cerebrolysin Ameliorates Focal Cerebral Ischemia Injury Through Neuroinflammatory Inhibition via CREB/PGC-1α Pathway

Neuroinflammation is one of the important factors aggravating brain injury after ischemic stroke. We aimed to investigate the effects of cerebrolysin (CBL) on neuroinflammation in vivo and in vitro and the underlying mechanisms. The gene expressions of pro-inflammatory factors and anti-inflammatory factors were analyzed by real time PCR in rat transient middle cerebral artery occlusion (tMCAO) model, lipopolysaccharides-induced neuroinflammatory mice model and LPS-treated mouse primary microglia cells. The neuroprotective effects of CBL were evaluated by infarct size, Longa test and Rotarod test for long-term functional recovery in rats subjected to ischemia. The role of CREB/PGC-1α pathway in anti-neuroinflammatory effect of CBL was also determined by real time PCR and Western blotting. In the tMCAO model, administration of CBL at 3 h post-ischemia reduced infarct volume, promoted long-term functional recovery, decreased the gene expression of pro-inflammatory factors and increased the gene expression of anti-inflammatory factors. Correspondingly, in LPS-induced neuroinflammatory mice model, CBL treatment attenuated sickness behavior, decreased the gene expression of pro-inflammatory factors, and increased the gene expression of anti-inflammatory factors. In in vitro and in vivo experiments, CBL increased the protein expression levels of PGC-1α and phosphorylated CREB to play anti-inflammatory effect. Additionally, the application of the specific CREB inhibitor, 666-15 compound could effectively reverse the anti-inflammatory effect of CBL in primary mouse microglia cells and anti-ischemic brain injury of CBL in rats subjected to tMCAO. In conclusion, CBL ameliorated cerebral ischemia injury through reducing neuroinflammation partly via the activation of CREB/PGC-1α pathway and may play a therapeutic role as anti-neuroinflammatory agents in the brain disorders associated with neuroinflammation.

Safety and efficacy of Cerebrolysin in acute brain injury and neurorecovery: CAPTAIN I-a randomized, placebo-controlled, double-blind, Asian-Pacific trial

OBJECTIVE

To evaluate the safety and efficacy of Cerebrolysin as an add-on therapy to local standard treatment protocol in patients after moderate-to-severe traumatic brain injury.

METHODS

The patients received the study medication in addition to standard care (50 mL of Cerebrolysin or physiological saline solution daily for 10 days, followed by two additional treatment cycles with 10 mL daily for 10 days) in a prospective, randomized, double-blind, placebo-controlled, parallel-group, multi-centre phase IIIb/IV trial. The primary endpoint was a multidimensional ensemble of 14 outcome scales pooled to be analyzed by means of the multivariate, correlation-sensitive Wei-Lachin procedure.

RESULTS

In 46 enrolled TBI patients (Cerebrolysin 22, placebo 24), three single outcomes showed stand-alone statistically significant superiority of Cerebrolysin [Stroop Word/Dots Interference (p = 0.0415, Mann-Whitney(MW) = 0.6816, 95% CI 0.51-0.86); Color Trails Tests 1 and 2 (p = 0.0223/0.0170, MW = 0.72/0.73, 95% CI 0.53-0.90/0.54-0.91), both effect sizes lying above the benchmark for "large" superiority (MW > 0.71)]. While for the primary multivariate ensemble, statistical significance was just missed in the intention-to-treat population (p_Wei-Lachin < 0.1, MW_combined = 0.63, 95% CI 0.48-0.77, derived standardized mean difference (SMD) 0.45, 95% CI -0.07 to 1.04, derived OR 2.1, 95% CI 0.89-5.95), the per-protocol analysis showed a statistical significant superiority of Cerebrolysin (p_Wei-Lachin = 0.0240, MW_combined = 0.69, 95% CI 0.53 to 0.85, derived SMD 0.69, 95% CI 0.09 to 1.47, derived OR 3.2, 95% CI 1.16 to 12.8), with effect sizes of six single outcomes lying above the benchmark for "large" superiority. Safety aspects were comparable to placebo.

CONCLUSION

Our trial suggests beneficial effects of Cerebrolysin on outcome after TBI. Results should be confirmed by a larger RCT with a comparable multidimensional approach.

Randomized controlled trial of Cerebrolysin's effects on long-term histological outcomes and functional recovery in rats with moderate closed head injury

OBJECTIVE

The authors previously demonstrated that Cerebrolysin is effective for treatment of mild closed head injury (CHI) when administered 4 hours after injury. The aim of this study was to determine Cerebrolysin's effects on functional and histological outcomes in rats subjected to moderate CHI.

METHODS

In this randomized, blinded, and vehicle-controlled preclinical trial, male adult Wistar rats subjected to moderate CHI received either Cerebrolysin treatment at a dose of 2.5 ml/kg (n = 13) or vehicle (saline, n = 13) intraperitoneally administered daily for 10 days, starting at 4 hours after injury. Animals were subjected to cognitive and sensorimotor functional tests at multiple time points, and they were killed 3 months after injury. The brains were processed for analyses of neuronal cell loss, amyloid precursor protein, axonal damage, and neurogenesis.

RESULTS

Compared with rats treated with vehicle (saline), rats treated with Cerebrolysin had significantly increased numbers of neuroblasts and newborn mature neurons in the dentate gyrus (DG) and attenuated amyloid precursor protein accumulation and axonal damage in various brain regions, as well as decreased neuronal loss in the DG and cornu ammonis 3 (CA3) region of the hippocampus (p < 0.05). Global testing using generalized estimating equations showed a significant beneficial effect of Cerebrolysin treatment on sensorimotor functional outcomes from 1 day to 3 months after injury compared to that of saline treatment (p < 0.05). Compared with vehicle-treated rats, Cerebrolysin-treated rats showed significantly and robustly improved long-term (up to 3 months) cognitive functional recovery, as measured by social interaction, Morris water maze, novel object recognition, and odor recognition tests. In the Cerebrolysin-treated rats there were significant correlations between multiple histological outcomes and functional recovery evident 3 months after moderate CHI, as indicated by Pearson partial correlation analyses.

CONCLUSIONS

The authors' findings demonstrate that Cerebrolysin treatment significantly improves long-term functional and histological outcomes in rats with moderate CHI, with functional outcomes significantly correlated with histological indices of neuroplasticity and neuroprotection. These data indicate that Cerebrolysin may be useful for the treatment of moderate CHI.

Cerebrolysin attenuates ethanol-induced spatial memory impairments through inhibition of hippocampal oxidative stress and apoptotic cell death in rats

The present study investigates the potential neuroprotective effect of cerebrolysin (CBL), a combination of neurotrophic factors, on the cognitive and biochemical alterations induced by chronic ethanol administration in rats. The animals were divided into five groups as follows: control; ethanol (4 g/kg, for 30 days) plus normal saline (Ethanol + NS); ethanol plus CBL 1 mL/kg (Ethanol + CBL 1), ethanol plus CBL 2.5 mL/kg (Ethanol + CBL 2.5); and ethanol plus CBL 5 mL/kg (Ethanol + CBL 5). The Morris water maze (MWM) test was performed to assess cognitive impairment. The status of the lipid peroxidation marker MDA, antioxidant capacity, as well as alterations of the apoptotic factors such as Bcl-2, BAX, and cleaved caspase-9 and -3, were evaluated in the hippocampus. The results showed that CBL treatment not only normalized the increased MDA levels in the alcoholic rats and enhanced antioxidant defense, but also reduced the Bax/Bcl-2 ratio and cleaved caspase-9 and -3 in the hippocampus. These results were parallel with improvement in spatial memory performance in the MWM test. The findings of the present study provide evidence for the promising therapeutic effect of CBL in chronic ethanol consumption through counteracting oxidative stress and apoptosis markers.

Identification of a Novel Peptide from β-Casein That Enhances Spatial and Object Recognition Memory in Mice

An increase in the aging population has spurred recent efforts to identify diet and lifestyle changes that help prevent cognitive decline. Several epidemiological investigations and clinical studies have indicated that consuming fermented dairy products prevents cognitive decline. Some peptides from whey including β-lactolin improve memory impairment; the intake of Camembert cheese has been shown to prevent Alzheimer's in mouse models. To elucidate the molecular mechanisms underlying these preventive effects, we screened peptides from digested casein protein for their ability to improve spatial memory in a scopolamine-induced amnesia mouse model. Administration of KEMPFPKYPVEP peptide from β-casein at 0.5 mg/kg (54.8 ± 2.5) and 2 mg/kg (57.9 ± 3.7) improved memory impairment in the amnesia mice in comparison with control (44.9 ± 3.4; p = 0.031 and p = 0.042, respectively) and increased dopamine (5.9 ± 3.8 [control] and 12.4 ± 6.2 [KEMPFPKYPVEP peptide]) and norepinephrine (7.7 ± 0.8 [control] and 9.9 ± 2.0 [KEMPFPKYPVEP peptide]) levels in the frontal cortex (p = 0.039 and p = 0.031, respectively). Collectively, our findings suggest that peptides in fermented dairy products prevent cognitive decline and support previously reported observations.

Prospective, double blinded, comparative assessment of the pharmacological activity of Cerebrolysin and distinct peptide preparations for the treatment of embolic stroke

BACKGROUND

Our previous work in acute ischemic stroke and TBI models focused on efficacy and pharmacological parameters of Cerebrolysin®. In this prospective, randomized, blinded, placebo-controlled study we compared efficacy of neuropeptide preparations with putative neurotrophic potential to the reference product Cerebrolysin® by assessing functional outcome and lesion volumes after embolic stroke in a rodent model.

METHODS

Male Wistar rats were subjected to embolic right middle cerebral artery occlusion and were treated with: 1) Cognistar® (Cerebroprotein Hydrolysate) 2.5 ml/kg, 2) Cerebrolysat® 2.5 ml/kg, 3) Cortexin® 1.7 mg/kg, 4) Cerebrolysin® 2.5 ml/kg, or 5) 1 ml of saline according to a pre-generated randomization plan. Dosages were defined according to the packet leaflet of the corresponding preparation and were adapted to the animal model as previously described. All enrolled rats received intraperitoneal injections once daily for 10 consecutive days, starting 4 h after occlusion. Functional outcome was assessed once weekly over four weeks by using a battery of behavioral tests. Infarct volume was measured four weeks after occlusion. Generalized Estimation Equations (GEE) was performed to study the treatment effect on overall functional recovery at day 28 (primary outcome), compared to saline controls.

RESULTS

Similar functional outcome was observed for saline control, Cognistar®, Cerebrolysat® and Cortexin®; in contrast, a significantly improved neurological outcome was observed with Cerebrolysin® treatment in comparison to saline as well as to the comparator drug treatment (p < .002). However, there was no significant difference in lesion volumes between rats treated with either Cortexin® (33.5 ± 1.9%), Cerebrolysat® (28.5 ± 2.4%), Cognistar® (34.7 ± 2.0%), or Cerebrolysin® (26.5 ± 2.3%) compared to saline-treated rats (30.8 ± 2.1%).

CONCLUSION

Among all tested neuropeptide preparations, Cerebrolysin® was the only agent that was associated with a significant improvement of neurological outcome after stroke.

Cerebrolysin Reduces Astrogliosis and Axonal Injury and Enhances Neurogenesis in Rats After Closed Head Injury

BACKGROUND

Cerebrolysin is a neuropeptide preparation with neuroprotective and neurotrophic properties. Our previous study demonstrates that cerebrolysin significantly improves functional recovery in rats after mild traumatic brain injury (mTBI).

OBJECTIVE

To determine histological outcomes associated with therapeutic effects of cerebrolysin on functional recovery after TBI.

METHODS

In this prospective, randomized, blinded, and placebo-controlled study, adult Wistar rats with mild TBI induced by a closed head impact were randomly assigned to one of the cerebrolysin dose groups (0.8, 2.5, 7.5 mL/kg) or placebo, which were administered 4 hours after TBI and then daily for 10 consecutive days. Functional tests assessed cognitive, behavioral, motor, and neurological performance. Study end point was day 90 after TBI. Brains were processed for histological tissue analyses of astrogliosis, axonal injury, and neurogenesis.

RESULTS

Compared with placebo, cerebrolysin significantly reduced amyloid precursor protein accumulation, astrogliosis, and axonal damage in various brain regions and increased the number of neuroblasts and neurogenesis in the dentate gyrus. There was a significant dose effect of cerebrolysin on functional outcomes at 3 months after injury compared with saline treatment. Cerebrolysin at a dose of ⩾0.8 mL/kg significantly improved cognitive function, whereas at a dose of ⩾2.5 mL/kg, cerebrolysin also significantly improved sensorimotor function at various time points. There were significant correlations between multiple histological and functional outcomes 90 days after mTBI.

CONCLUSIONS

Our findings demonstrate that cerebrolysin reduces astrogliosis and axonal injury and promotes neurogenesis, which may contribute to improved functional recovery in rats with mTBI.

Effects of cerebrolysin on functional outcome of patients with traumatic brain injury: a systematic review and meta-analysis

BACKGROUND

Traumatic brain injury (TBI) remains a main public health problem being associated with high mortality and morbidity. The functional outcome of TBI remains unfavorable despite several surgical and medical therapies. Cerebrolysin is a neuropeptide with potential neuroregenerative entities.

OBJECTIVE

The aim of the current systematic review and meta-analysis was to investigate the effects of cerebrolysin on functional outcome in patients with moderate and severe TBI.

DATA SOURCES

Online databases used included Medline, Scopus, EMBASE, Google Scholar, Web of Science, and Cochrane Library.

STUDY ELIGIBILITY CRITERIA

All the relevant studies with randomized clinical trial and cohort design evaluating the effects of intravenous cerebrolysin vs placebo on functional outcome of patients with TBI within the English literature up to October 2018 were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

The articles were reviewed by two independent authors and the data were extracted to a data sheet. I 2 and Cochran's Q-statistics were used to assess heterogeneity. Based on the presence of significant heterogeneity across included studies, data were pooled using random-effects model with Dersimonian-Laird method and presented as standardized mean differences (SMDs) and corresponding 95% CI.

RESULTS

Five articles (5,685 participants) were included in the current meta-analysis. The overall pooled findings using random-effects models among patients with TBI indicated that intravenous administration of cerebrolysin significantly increased Glasgow Outcome Scale score (SMD =0.30; 95% CI: 0.18 to 0.42; P<0.001; I 2: 87.8%) and decreased modified Rankin Scale score (SMD =-0.29; 95% CI: -0.42 to 0.16; P=0.05; I 2: 89.6%).

LIMITATIONS

The results are mainly based on cohort studies and there is a lack of clinical trials in the literature. There is also heterogeneity among the studies regarding the dosage and duration of administration and the measurement of functional outcome.

CONCLUSION

The results of the current study revealed that intravenous administration of cerebrolysin is associated with improved functional outcome in patients with TBI measured by the Glasgow Outcome Scale and the modified Rankin Scale scores.

Stem cells technology: a powerful tool behind new brain treatments

Stem cell research has recently become a hot research topic in biomedical research due to the foreseen unlimited potential of stem cells in tissue engineering and regenerative medicine. For many years, medicine has been facing intense challenges, such as an insufficient number of organ donations that is preventing clinicians to fulfill the increasing needs. To try and overcome this regrettable matter, research has been aiming at developing strategies to facilitate the in vitro culture and study of stem cells as a tool for tissue regeneration. Meanwhile, new developments in the microfluidics technology brought forward emerging cell culture applications that are currently allowing for a better chemical and physical control of cellular microenvironment. This review presents the latest developments in stem cell research that brought new therapies to the clinics and how the convergence of the microfluidics technology with stem cell research can have positive outcomes on the fields of regenerative medicine and high-throughput screening. These advances will bring new translational solutions for drug discovery and will upgrade in vitro cell culture to a new level of accuracy and performance. We hope this review will provide new insights into the understanding of new brain treatments from the perspective of stem cell technology especially regarding regenerative medicine and tissue engineering.

Prevention of memory impairment induced by post-traumatic stress disorder by cerebrolysin

Post-traumatic stress disorder (PTSD) may occur after exposure to stressful, fearful or troubling events. Until now, there is no curable medication for this disorder. Cerebrolysin is a neuropeptide, which has an important role in the treatment of vascular dementia. In this study, the probable protective effect of cerebrolysin on PTSD-induced memory impairment was investigated. To induce PTSD, the single prolonged stress (SPS) model was used. Rats were allocated into four groups: control (vehicle-treated), CBL (administrated cerebrolysin 2.5 ml/kg by intraperitoneal route for 4 weeks), SPS (as a model of PTSD and administered vehicle), and CBL-SPS (exposed to SPS and administered cerebrolysin for 4 weeks). Learning and memory were assessed using the radial arm water maze (RAWM). Results showed that SPS impaired both short- and long- term memories; and chronic cerebrolysin administration prevented such effect. Cerebrolysin also prevented decreases in hippocampal GSH levels and GSH/GSSG ratios, and increased GSSG and TBARs, levels induced by PTSD. In conclusion, a protective effect of cerebrolysin administration against SPS model of PTSD induced short- and long- term memory impairment was characterized. This protection could be accomplished, at least partly, by prevention of PTSD induced increase in oxidative stress in the hippocampus via the use of cerebrolysin.

Prospective, randomized, blinded, and placebo-controlled study of Cerebrolysin dose-response effects on long-term functional outcomes in a rat model of mild traumatic brain injury

OBJECTIVE

Cerebrolysin is a neuropeptide preparation that mimics the properties of neurotrophic factors and has had beneficial effects in the treatment of neurodegenerative diseases, stroke, and traumatic brain injury (TBI). To further evaluate treatment schemes, the authors assessed the dose-response of Cerebrolysin on functional improvement in a rat model of mild TBI (mTBI).

METHODS

This dose-response study was a prospective, randomized, blinded, and placebo-controlled preclinical experiment. Male Wistar adult rats, subjected to mTBI induced by a closed head impact, were treated randomly with 0 (saline as placebo), 0.8, 2.5, or 7.5 ml/kg of Cerebrolysin 4 hours after mTBI and daily for a total of 10 consecutive days. A battery of cognitive and sensorimotor functional tests was performed over 90 days.

RESULTS

The primary outcome was functional improvement over the 90 days; animal weight and death were the secondary and safety outcomes, respectively. A significant (p < 0.001) dose effect of Cerebrolysin on cognitive recovery 3 months after injury was found. Cerebrolysin at a dose of ≥ 0.8 ml/kg significantly (p < 0.001) improved cognitive outcome. The higher dose (7.5 ml/kg) resulted in significantly better cognitive recovery than the lowest doses (0.8 ml/kg) but not relative to the 2.5-ml/kg dose. Cerebrolysin at a dose of 2.5 or 7.5 ml/kg also caused different onset times of significant improvement in sensorimotor function. No differences in body weight or mortality rate among the groups were found.

CONCLUSIONS

This preclinical randomized, placebo-controlled, and blinded study with a clinically relevant treatment scheme revealed that Cerebrolysin at doses of 0.8–7.5 ml/kg, administered 4 hours after mTBI and then once daily for a total of 10 consecutive days, improved functional outcomes 3 months after injury. A dose of 2.5 ml/kg is likely an optimal dose for the treatment of experimental mTBI.

Intranasal cerebrolysin improves cognitive function and structural synaptic plasticity in photothrombotic mouse model of medial prefrontal cortex ischemia

Medial prefrontal cortex (mPFC) ischemia affects post-stroke cognitive outcomes. We aimed to investigate the effects of different doses and routes of cerebrolysin (CBL) on the structural synaptic plasticity and cognitive function after mPFC ischemia in mice. Thence, CBL (1, 2.5 ml/kg/i.p./daily) or (1 ml/kg/i.n./daily), were administrated in photothrombotic mouse model of mPFC ischemia for two weeks. Episodic and spatial memories were assessed by the What-Where-Which (WWWhich) and Barnes tasks. Growth-associated protein 43 (GAP-43), postsynaptic density-95 (PSD-95), and synaptophysin (SYN) levels were measured in the lesioned area using western blot analysis. Dendritic arbors, spine densities, and morphology were assessed via Golgi-Cox staining. Treatment with 2.5 ml/kg/i.p. and 1 ml/kg/i.n. doses attenuated mPFC ischemia-induced episodic and spatial memories impairment. Results showed an obvious increase in the GAP-43, PSD-95 and SYN levels and improvement in the structural synaptic indexes in lesioned area induced by the same doses and routes of CBL. In conclusion, we found that specific doses/routes of CBL have positive effects on the structural synaptic plasticity and cognitive outcomes after mPFC ischemia.

A Small Molecule Spinogenic Compound Enhances Functional Outcome and Dendritic Spine Plasticity in a Rat Model of Traumatic Brain Injury

The tetra (ethylene glycol) derivative of benzothiazole aniline (SPG101) has been shown to improve dendritic spine density and cognitive memory in the triple transgenic mouse model of Alzheimer disease (AD) when administered intraperitoneally. The present study was designed to investigate the therapeutic effects of SPG101 on dendritic spine density and morphology and sensorimotor and cognitive functional recovery in a rat model of traumatic brain injury (TBI) induced by controlled cortical impact (CCI). Young adult male Wistar rats with CCI were randomly divided into the following two groups (n = 7/group): (1) Vehicle, and (2) SPG101. SPG101 (30 mg/kg) dissolved in vehicle (1% dimethyl sulfoxide in phosphate buffered saline) or Vehicle were intraperitoneally administered starting at 1 h post-injury and once daily for the next 34 days. Sensorimotor deficits were assessed using a modified neurological severity score and adhesive removal and foot fault tests. Cognitive function was measured by Morris water maze, novel object recognition (NOR), and three-chamber social recognition tests. The animals were sacrificed 35 days after injury, and their brains were processed for measurement of dendritic spine density and morphology using ballistic dye labeling. Compared with the vehicle treatment, SPG101 treatment initiated 1 h post-injury significantly improved sensorimotor functional recovery (days 7-35, p < 0.0001), spatial learning (days 32-35, p < 0.0001), NOR (days 14 and 35, p < 0.0001), social recognition (days 14 and 35, p < 0.0001). Further, treatment significantly increased dendritic spine density in the injured cortex (p < 0.05), decreased heterogeneous distribution of spine lengths in the injured cortex and hippocampus (p < 0.0001), modifications that are associated with the promotion of spine maturation in these brain regions. In summary, treatment with SPG101 initiated 1 h post-injury and continued for an additional 34 days improves both sensorimotor and cognitive functional recovery, indicating that SPG101 acts as a spinogenic agent and may have potential as a novel treatment of TBI.

Novel lactopeptides in fermented dairy products improve memory function and cognitive decline

Alongside the rapid growth in aging populations, prevention of age-related memory decline and dementia has become a high priority. Several epidemiological and clinical studies have concluded that fermented dairy products can help to prevent cognitive decline; furthermore, intake of Camembert cheese prevents Alzheimer's pathology in model mice. To elucidate molecular mechanisms underlying the preventive effects of fermented dairy products, here we screened peptides from digested fermented dairy products for ability to improve memory function in a scopolamine-induced amnesia mouse model. We found that Trp-Tyr (WY)-containing peptides from whey protein improved memory function in the mice, and the effects were confirmed in aged mice. The WY-containing peptides directly inhibited monoamine oxidase-B activity and increased dopamine levels in brain tissue. Pretreatment with dopamine receptor antagonist abolished the improvement in memory function due to WY-containing peptides. These results suggest that WY-containing peptides in fermented dairy products increase monoamine levels by inhibiting monoamine oxidase-B activity, helping to prevent age-related cognitive decline.

Affective, neurocognitive and psychosocial disorders associated with traumatic brain injury and post-traumatic epilepsy

Survivors of traumatic brain injury (TBI) often develop chronic neurological, neurocognitive, psychological, and psychosocial deficits that can have a profound impact on an individual's wellbeing and quality of life. TBI is also a common cause of acquired epilepsy, which is itself associated with significant behavioral morbidity. This review considers the clinical and preclinical evidence that post-traumatic epilepsy (PTE) acts as a 'second-hit' insult to worsen chronic behavioral outcomes for brain-injured patients, across the domains of emotional, cognitive, and psychosocial functioning. Surprisingly, few well-designed studies have specifically examined the relationship between seizures and behavioral outcomes after TBI. The complex mechanisms underlying these comorbidities remain incompletely understood, although many of the biological processes that precipitate seizure occurrence and epileptogenesis may also contribute to the development of chronic behavioral deficits. Further, the relationship between PTE and behavioral dysfunction is increasingly recognized to be a bidirectional one, whereby premorbid conditions are a risk factor for PTE. Clinical studies in this arena are often challenged by the confounding effects of anti-seizure medications, while preclinical studies have rarely examined an adequately extended time course to fully capture the time course of epilepsy development after a TBI. To drive the field forward towards improved treatment strategies, it is imperative that both seizures and neurobehavioral outcomes are assessed in parallel after TBI, both in patient populations and preclinical models.

Diminished Dentate Gyrus Filtering of Cortical Input Leads to Enhanced Area Ca3 Excitability after Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) disrupts hippocampal function and can lead to long-lasting episodic memory impairments. The encoding of episodic memories relies on spatial information processing within the hippocampus. As the primary entry point for spatial information into the hippocampus, the dentate gyrus is thought to function as a physiological gate, or filter, of afferent excitation before reaching downstream area Cornu Ammonis (CA3). Although injury has previously been shown to alter dentate gyrus network excitability, it is unknown whether mTBI affects dentate gyrus output to area CA3. In this study, we assessed hippocampal function, specifically the interaction between the dentate gyrus and CA3, using behavioral and electrophysiological techniques in ex vivo brain slices 1 week following mild lateral fluid percussion injury (LFPI). Behaviorally, LFPI mice were found to be impaired in an object-place recognition task, indicating that spatial information processing in the hippocampus is disrupted. Extracellular recordings and voltage-sensitive dye imaging demonstrated that perforant path activation leads to the aberrant spread of excitation from the dentate gyrus into area CA3 along the mossy fiber pathway. These results suggest that after mTBI, the dentate gyrus has a diminished capacity to regulate cortical input into the hippocampus, leading to increased CA3 network excitability. The loss of the dentate filtering efficacy reveals a potential mechanism by which hippocampal-dependent spatial information processing is disrupted, and may contribute to memory dysfunction after mTBI.

Impact of Traumatic Brain Injury on Dopaminergic Transmission

Brain trauma is often associated with severe morbidity and is a major public health concern. Even when injury is mild and no obvious anatomic disruption is seen, many individuals suffer disabling neuropsychological impairments such as memory loss, mood dysfunction, substance abuse, and adjustment disorder. These changes may be related to subtle disruption of neural circuits as well as functional changes at the neurotransmitter level. In particular, there is considerable evidence that dopamine (DA) physiology in the nigrostriatal and mesocorticolimbic pathways might be impaired after traumatic brain injury (TBI). Alterations in DA levels can lead to oxidative stress and cellular dysfunction, and DA plays an important role in central nervous system inflammation. Therapeutic targeting of DA pathways may offer benefits for both neuronal survival and functional outcome after TBI. The purpose of this review is to discuss the role of DA pathology in acute TBI and the potential impact of therapies that target these systems for the treatment of TBI.

The Potential of Stem Cells in Treatment of Traumatic Brain Injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) is a global public health concern, with limited treatment options available. Despite improving survival rate after TBI, treatment is lacking for brain functional recovery and structural repair in clinic. Recent studies have suggested that the mature brain harbors neural stem cells which have regenerative capacity following brain insults. Much progress has been made in preclinical TBI model studies in understanding the behaviors, functions, and regulatory mechanisms of neural stem cells in the injured brain. Different strategies targeting these cell population have been assessed in TBI models. In parallel, cell transplantation strategy using a wide range of stem cells has been explored for TBI treatment in pre-clinical studies and some in clinical trials. This review summarized strategies which have been explored to enhance endogenous neural stem cell-mediated regeneration and recent development in cell transplantation studies for post-TBI brain repair.

RECENT FINDINGS

Thus far, neural regeneration through neural stem cells either by modulating endogenous neural stem cells or by stem cell transplantation has attracted much attention. It is highly speculated that targeting neural stem cells could be a potential strategy to repair and regenerate the injured brain. Neuroprotection and neuroregeneration are major aspects for TBI therapeutic development. With technique advancement, it is hoped that stem cell-based therapy targeting neuroregeneration will be able to translate to clinic in not so far future.

Pathophysiology and Treatment of Memory Dysfunction After Traumatic Brain Injury

Memory is fundamental to everyday life, and cognitive impairments resulting from traumatic brain injury (TBI) have devastating effects on TBI survivors. A contributing component to memory impairments caused by TBI is alteration in the neural circuits associated with memory function. In this review, we aim to bring together experimental findings that characterize behavioral memory deficits and the underlying pathophysiology of memory-involved circuits after TBI. While there is little doubt that TBI causes memory and cognitive dysfunction, it is difficult to conclude which memory phase, i.e., encoding, maintenance, or retrieval, is specifically altered by TBI. This is most likely due to variation in behavioral protocols and experimental models. Additionally, we review a selection of experimental treatments that hold translational potential to mitigate memory dysfunction following injury.

Short-term caloric restriction exerts neuroprotective effects following mild traumatic brain injury by promoting autophagy and inhibiting astrocyte activation

Cognitive deficits may occur after mild traumatic brain injury (mTBI), but effective treatment modalities are presently unavailable. Caloric restriction (CR) has beneficial effects on neurodegenerative diseases and brain injury. However, the underlying mechanisms have not yet been clearly defined. Therefore, the aim of the present study was to investigate the short-term effects of CR treatment on cognitive function in mice after mTBI. Forty-five 12-week-old C57/BL6 mice were subjected to closed-head mTBI using a weight drop device. The mice were then randomly divided into three groups according to their diet for 30 days: the normal calorie group (mTBI+NC group, n=15), the caloric restriction group (mTBI+CR group, n=15), and the high energy group (mTBI+HE group, n=15). After 30 days, the Morris water maze test was performed to evaluate learning abilities. Nissl staining, immunohistochemistry, and western blotting were used to monitor pathological changes and changes in autophagy-associated proteins in the hippocampus. The average escape latency was significantly shorter in the mTBI+CR group than in the mTBI+NC and mTBI+HE groups, and the number of target platform crossings in the mTBI+CR group was significantly higher than in the other two groups. In the hippocampus, the expression of GFAP and mTOR was increased in the mTBI+HE group and decreased in the mTBI+CR group. Conversely, the expression of LC3B was decreased in the mTBI+HE group and increased in the mTBI+CR group. Our findings suggest that short-term CR after mTBI may ameliorate cognitive dysfunction induced by mTBI by increasing the level of autophagy and suppressing astrocyte activation.

Bidirectional relationship of mast cells-neurovascular unit communication in neuroinflammation and its involvement in POCD

Postoperative cognitive dysfunction (POCD) has been hypothesized to be mediated by surgery-induced neuroinflammation, which is also a key element in the pathobiology of neurodegenerative diseases, stroke, and neuropsychiatric disorders. There is extensive communication between the immune system and the central nervous system (CNS). Inflammation resulting from activation of the innate immune system cells in the periphery can impact central nervous system behaviors, such as cognitive performance. Mast cells (MCs), as the"first responders" in the CNS, can initiate, amplify, and prolong other immune and nervous responses upon activation. In addition, MCs and their secreted mediators modulate inflammatory processes in multiple CNS pathologies and can thereby either contribute to neurological damage or confer neuroprotection. Neuroinflammation has been considered to be linked to neurovascular dysfunction in several neurological disorders. This review will provide a brief overview of the bidirectional relationship of MCs-neurovascular unit communication in neuroinflammation and its involvement in POCD, providing a new and unique therapeutic target for the adjuvant treatment of POCD.

Intranasal Cerebrolysin Attenuates Learning and Memory Impairments in D-galactose-Induced Senescence in Mice

Neurotrophic factors are currently being considered as pro-cognitive therapeutic approaches for management of cognitive deficits. This study aims to evaluate the effects of intranasal (i.n.) or intraperitoneal (i.p.) administration of Cerebrolysin (CBL) (as a mixture of neurotrophic factors) on the d-galactose-induced oxidative stress, apoptosis and memory as well as learning impairment in mice. For this purpose, CBL (1, 2.5, 5 ml/kg/i.p.) or (1 ml/kg/i.n.), were administrated daily in d-galactose-received (100 mg/kg/subcutaneous (s.c.)) mice model of aging for eight weeks. Spatial and recognition memories were assessed by the Morris water maze and novel object recognition tasks. Brain and blood of animals were analysed for oxidative stress biomarkers including malondialdehyde, total antioxidant capacity, glutathione peroxidase and superoxide dismutase. Apoptosis rate in the hippocampus was evaluated by TUNEL staining of brain tissue. 5 ml/kg/i.p. dose of CBL increased the locomotor activity but, 1 ml/kg/i.p. dose didn't show detectable behavioural or molecular effects on aged mice. Treatment with 2.5 ml/kg/i.p. and 1 ml/kg/i.n. doses attenuated d-galactose-impaired spatial and recognition memories. Results showed an obvious increase in the antioxidant biomarkers and decrease in the malondialdehyde levels both in the blood and brain of aged mice in 2.5 ml/kg/i.p. dose, and only in the brain in 1 ml/kg/i.n. dose of CBL. Anti-apoptotic effects also were seen in the same dose/rout of CBL administration in aged animals. This study proves the usefulness of i.n. CBL administration as a non-invasive and efficient method of drug delivery to the brain to improve aging-induced oxidative stress, apoptosis and learning as well as memory impairment.

In Vivo Expression of Reprogramming Factors Increases Hippocampal Neurogenesis and Synaptic Plasticity in Chronic Hypoxic-Ischemic Brain Injury

Neurogenesis and synaptic plasticity can be stimulated in vivo in the brain. In this study, we hypothesized that in vivo expression of reprogramming factors such as Klf4, Sox2, Oct4, and c-Myc would facilitate endogenous neurogenesis and functional recovery. CD-1® mice were induced at 1 week of age by unilaterally carotid artery ligation and exposure to hypoxia. At 6 weeks of age, mice were injected GFP only or both four reprogramming factors and GFP into lateral ventricle. Passive avoidance task and open field test were performed to evaluate neurobehavioral function. Neurogenesis and synaptic activity in the hippocampus were evaluated using immunohistochemistry, qRT-PCR, and/or western blot analyses. Whereas BrdU⁺GFAP⁺ cells in the subgranular zone of the hippocampus were not significantly different, the numbers of BrdU⁺βIII-tubulin⁺ and BrdU⁺NeuN⁺ cells were significantly higher in treatment group than control group. Expressions of synaptophysin and PSD-95 were also higher in treatment group than control group. Importantly, passive avoidance task and open field test showed improvement in long-term memory and decreased anxiety in treatment group. In conclusion, in vivo expression of reprogramming factors improved behavioral functions in chronic hypoxic-ischemic brain injury. The mechanisms underlying these repair processes included endogenous neurogenesis and synaptic plasticity in the hippocampus.

Knockout of Cyclophilin-D Provides Partial Amelioration of Intrinsic and Synaptic Properties Altered by Mild Traumatic Brain Injury

Mitochondria are central to cell survival and Ca²⁺ homeostasis due to their intracellular buffering capabilities. Mitochondrial dysfunction resulting in mitochondrial permeability transition pore (mPTP) opening has been reported after mild traumatic brain injury (mTBI). Cyclosporine A provides protection against the mPTP opening through its interaction with cyclophilin-D (CypD). A recent study has found that the extent of axonal injury after mTBI was diminished in neocortex in cyclophilin-D knockout (CypDKO) mice. Here we tested whether this CypDKO could also provide protection from the increased intrinsic and synaptic neuronal excitability previously described after mTBI in a mild central fluid percussion injury mice model. CypDKO mice were crossed with mice expressing yellow fluorescent protein (YFP) in layer V pyramidal neurons in neocortex to create CypDKO/YFP-H mice. Whole cell patch clamp recordings from axotomized (AX) and intact (IN) YFP+ layer V pyramidal neurons were made 1 and 2 days after sham or mTBI in slices from CypDKO/YFP-H mice. Both excitatory post synaptic currents (EPSCs) recorded in voltage clamp and intrinsic cellular properties, including action potential (AP), afterhyperpolarization (AHP), and depolarizing after potential (DAP) characteristics recorded in current clamp were evaluated. There was no significant difference between sham and mTBI for either spontaneous or miniature EPSC frequency, suggesting that CypDKO ameliorates excitatory synaptic abnormalities. There was a partial amelioration of intrinsic properties altered by mTBI. Alleviated were the increased slope of the AP frequency vs. injected current plot, the increased AP, AHP and DAP amplitudes. Other properties that saw a reversal that became significant in the opposite direction include the current rheobase and AP overshoot. The AP threshold remained depolarized and the input resistance remained increased in mTBI compared to sham. Additional altered properties suggest that the CypDKO likely has a direct effect on membrane properties, rather than producing a selective reduction of the effects of mTBI. These results suggest that inhibiting CypD after TBI is an effective strategy to reduce synaptic hyperexcitation, making it a continued target for potential treatment of network abnormalities.

Treatment of traumatic brain injury in rats with N-acetyl-seryl-aspartyl-lysyl-proline

OBJECTIVE The authors' previous studies have suggested that thymosin beta 4 (Tβ4), a major actin-sequestering protein, improves functional recovery after neural injury. N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an active peptide fragment of Tβ4. Its effect as a treatment of traumatic brain injury (TBI) has not been investigated. Thus, this study was designed to determine whether AcSDKP treatment improves functional recovery in rats after TBI. METHODS Young adult male Wistar rats were randomly divided into the following groups: 1) sham group (no injury); 2) TBI + vehicle group (0.01 N acetic acid); and 3) TBI + AcSDKP (0.8 mg/kg/day). TBI was induced by controlled cortical impact over the left parietal cortex. AcSDKP or vehicle was administered subcutaneously starting 1 hour postinjury and continuously for 3 days using an osmotic minipump. Sensorimotor function and spatial learning were assessed using a modified Neurological Severity Score and Morris water maze tests, respectively. Some of the animals were euthanized 1 day after injury, and their brains were processed for measurement of fibrin accumulation and neuroinflammation signaling pathways. The remaining animals were euthanized 35 days after injury, and brain sections were processed for measurement of lesion volume, hippocampal cell loss, angiogenesis, neurogenesis, and dendritic spine remodeling. RESULTS Compared with vehicle treatment, AcSDKP treatment initiated 1 hour postinjury significantly improved sensorimotor functional recovery (Days 7-35, p < 0.05) and spatial learning (Days 33-35, p < 0.05), reduced cortical lesion volume, and hippocampal neuronal cell loss, reduced fibrin accumulation and activation of microglia/macrophages, enhanced angiogenesis and neurogenesis, and increased the number of dendritic spines in the injured brain (p < 0.05). AcSDKP treatment also significantly inhibited the transforming growth factor-β1/nuclear factor-κB signaling pathway. CONCLUSIONS AcSDKP treatment initiated 1 hour postinjury provides neuroprotection and neurorestoration after TBI, indicating that this small tetrapeptide has promising therapeutic potential for treatment of TBI. Further investigation of the optimal dose and therapeutic window of AcSDKP treatment for TBI and the associated underlying mechanisms is therefore warranted.

Social dysfunction after pediatric traumatic brain injury: A translational perspective

Social dysfunction is common after traumatic brain injury (TBI), contributing to reduced quality of life for survivors. Factors which influence the development or persistence of social deficits after injury remain poorly understood, particularly in the context of ongoing brain maturation during childhood and adolescence. Aberrant social interactions have recently been modeled in adult and juvenile rodents after experimental TBI, providing an opportunity to gain new insights into the underlying neurobiology of these behaviors. Here, we review our current understanding of social dysfunction in both humans and rodent models of TBI, with a focus on brain injuries acquired during early development. Modulators of social outcomes are discussed, including injury-related and environmental risk and resilience factors. Disruption of social brain network connectivity and aberrant neuroendocrine function are identified as potential mechanisms of social impairments after pediatric TBI. Throughout, we highlight the overlap and disparities between outcome measures and findings from clinical and experimental approaches, and explore the translational potential of future research to prevent or ameliorate social dysfunction after childhood TBI.

Strategies targeting endogenous neurogenic cell response to improve recovery following traumatic brain injury

Traumatic brain injury (TBI) affects over 1.7 million people in the United States alone and poses many clinical challenges due to the variability of the injuries and complexity of biochemical mechanisms involved. Thus far, there is still no effective therapy for TBI. Failure of preventative therapeutic strategies has led studies focusing on regenerative approaches. Recent studies have shown evidence that mature brains harbors multipotent neural stem cells capable of becoming mature neurons in the neurogenic regions. Following brain insults including TBI, the injured brain has increased level of neurogenic response in the subventricular zone and dentate gyrus of the hippocampus and this endogenous response is associated with cognitive function following injury. In this review, we highlight recent development and strategies aimed at targeting this endogenous cell response to enhance post-TBI functional recovery. This article is part of a Special Issue entitled SI:Brain injury and recovery.

Brain Region-Specific Histopathological Effects of Varying Trajectories of Controlled Cortical Impact Injury Model of Traumatic Brain Injury

AIMS

Traumatic brain injury (TBI) occurs when the head is impacted by an external force causing either a closed or penetrating head injury through a direct or accelerating impact. In laboratory research, most of the TBI animal models focus on a specific region to cause brain injury, but traumatic injuries in patients do not always impact the same brain regions. The aim of this study was to examine the histopathological effects of different angles of mechanical injury by manipulating the trajectory of the controlled cortical impact injury (CCI) model in adult Sprague-Dawley rats.

METHODS

The CCI model was manipulated as follows: conventional targeting of the frontal cortex, farthest right angle targeting the frontal cortex, closest right angle targeting the frontal cortex, olfactory bulb injury, and cerebellar injury. Three days after TBI, brains were harvested to analyze cortical and hippocampal cell loss, neuroinflammatory response, and neurogenesis via immunohistochemistry.

RESULTS

Results revealed cell death in the M1 region of the cortex across all groups, and in the CA3 area from olfactory bulb injury group. This observed cell death involved upregulation of inflammation as evidenced by rampant MHCII overexpression in cortex, but largely spared Ki-67/nestin neurogenesis in the hippocampus during this acute phase of TBI.

CONCLUSION

These results indicate a trajectory-dependent injury characterized by exacerbation of inflammation and different levels of impaired cell proliferation and neurogenesis. Such multiple brain areas showing varying levels of cell death after region-specific CCI model may closely mimic the clinical manifestations of TBI.